United Nations Secretary-General Kofi Annan has said the US-led invasion of Iraq was illegal because it violated the UN Charter.
He also questioned whether Iraq could hold elections in January if violence persisted.
Mr Annan, in an interview with the BBC, said the 15-member Security Council should have approved the invasion of Iraq in mid-March 2003.
Questioned repeatedly whether he considered the war illegal, Mr Annan said, "Yes, if you wish. I have indicated it was not in conformity with the UN Charter from our point of view, from the chapter point of view, it was illegal.
"I hope we don't see another Iraq-type operation for a long time . . . without UN approval and much broader support from the international community," Mr Annan added.
Mr Annan made a similar comment on March 10th, 2003 during a news conference shortly before the invasion. He said that if the United States took military action without Security Council approval "it would not be in conformity with the Charter".
The United States and Britain withdrew a draft resolution in the council in mid-March after it was clear there were not enough votes. France had threatened to veto if UN inspectors were not given more time to account for Saddam Hussein's weapons of mass destruction.
The secretary-general, in a report to the council last week, said the persistent violence in Iraq would make it difficult to hold elections as planned in January. The United Nations has advised Iraqi officials on the polls.
In the BBC interview, Mr Annan said: "You cannot have credible elections if the security conditions continue as they are now."